Wheelchair backrest assembly

Abstract

A seat assembly including a seat, a support plate configured to pivot with respect to the seat, a slide plate slidably mounted to the support plate, and a pivot arm positioned between the support plate and the slide plate and connected to the slide plate and the seat. When the support plate is pivotally adjusted with respect to the seat, the pivot arm causes the slide plate to slide along the support plate.

The invention claimed is: 
     
       1. A seat assembly comprising:
 a seat, 
 a support plate configured to pivot with respect to the seat; 
 a slide plate slidably mounted to the support plate, wherein the support plate has a width that is at least half the width of the slide plate; and 
 a pivot arm positioned between the support plate and the slide plate and connected to the slide plate and the seat; 
 wherein, when the support plate is pivotally adjusted with respect to the seat, the pivot arm causes the slide plate to slide along the support plate. 
 
     
     
       2. The seat assembly of  claim 1 , further including a link that is operatively connected to the pivot arm. 
     
     
       3. The seat assembly of  claim 2 , wherein the link is connected to the seat. 
     
     
       4. The seat assembly of  claim 2 , wherein the link is connected to a frame member. 
     
     
       5. The seat assembly of  claim 2 , wherein the link is connected to a post. 
     
     
       6. The seat assembly of  claim 1 , wherein the slide plate includes a slot. 
     
     
       7. The seat assembly of  claim 6 , wherein the pivot arm includes a protrusion that is slidably retained in the slot. 
     
     
       8. The seat assembly of  claim 1 , wherein, when the support plate is adjusted toward a reclined position, the slide plate slides toward the seat. 
     
     
       9. The seat assembly of  claim 1 , wherein the system is attached to a wheelchair. 
     
     
       10. A seat assembly comprising:
 a seat, 
 a support plate pivotally connected to the seat and that pivots with respect to the seat; 
 a slide plate slidably mounted to a front side of the support plate, wherein the support plate has a width that is at least half the width of the slide plate; and 
 a pivot arm positioned between the support plate and the slide plate and connected to the slide plate; 
 wherein, when the support plate is pivotally adjusted with respect to the seat, the pivot arm causes the slide plate to slide along the support plate. 
 
     
     
       11. The seat assembly of  claim 10 , further including a link that is operatively connected to the pivot arm and to a frame member of the seat. 
     
     
       12. The seat assembly of  claim 11 , wherein the link is connected to a post on the frame member. 
     
     
       13. The seat assembly of  claim 10 , wherein, when the support plate is adjusted toward the reclined position, the slide plate slides toward the seat. 
     
     
       14. The seat assembly of  claim 10 , wherein the seat assembly is attached to a wheelchair. 
     
     
       15. A seat assembly for a wheelchair comprising:
 a seat, 
 a support plate configured to pivot with respect to the seat; 
 a slide plate connected to the support plate and configured to slide with respect to the support plate, wherein the support plate has a width that is at least half the width of the slide plate; and 
 a pivot arm positioned between the support plate and the slide plate and rotatably connected to the support plate and connected to the slide plate by a slot and stud connection wherein the stud can slide within the slot; 
 wherein, when the support plate is pivotally adjusted with respect to the seat, the pivot arm causes the slide plate to slide with respect to the support plate.